Prevalence and genetic diversity of Enterocytozoon bieneusi in sheep in China

Heng Yang,Xiangan Han,Haiyan Jia,Rongsheng Mi,Yehua Zhang,Long Cheng,Xu Wang,Rui An,Zhaoguo Chen,Yan Huang,Xiaoli Zhang

doi:10.1186/s13071-018-3178-9

Heng Yang, Xiangan Han + Show 9 more

Open Access

https://doi.org/10.1186/s13071-018-3178-9

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Abstract

BackgroundEnterocytozoon bieneusi is a common species of microsporidia that not only influences human health but also threatens animal productive performance and value. However, there have been no systematic studies of the prevalence of E. bieneusi in sheep in China.ResultsA total of 953 fecal specimens were collected from sheep from 11 provinces across five regions of China and analyzed for E. bieneusi by nested PCR targeting the ribosomal internal transcribed spacer (ITS). Enterocytozoon bieneusi infections were detected in four regions, with an overall infection rate of 20.4% (194/953). The highest infection rate was detected in pre-weaned lambs (25.0%), followed by post-weaned lambs (22.2%) and adult sheep (14.6%). Enterocytozoon bieneusi was found in nine of the 11 tested provinces, with infection rates between 2.9–51.7%. Eleven genotypes were identified based on ITS analysis, including seven known genotypes (BEB6, CHG1, CHG3, CHS7, CHS8, COS-I and NESH5) and four novel genotypes (CHHLJS1, CHHLJS2, CHNXS1 and CHXJS1). All 11 genotypes were clustered into group 2, and the zoonotic genotype BEB6 was the dominant genotype (n = 129, 66.5%) in sheep.ConclusionThe prevalence of E. bieneusi was studied in five regions representing most areas where sheep are bred in China. This is the first report of E. bieneusi infection in sheep for seven Chinese provinces. Geographical differences were detected in the distribution of E. bieneusi genotypes, but no differences were found among sheep in different age groups. The zoonotic genotype BEB6 was the dominant genotype, indicating that sheep are a potential source of zoonotic microsporidiosis in China. These results improve our knowledge of the epidemiology of E. bieneusi in sheep in China.

Highlights

Enterocytozoon bieneusi is a common species of microsporidia that influences human health and threatens animal productive performance and value
Polymorphisms in the ribosomal internal transcribed spacer (ITS) of the Small subunit ribosomal RNA (rRNA) gene have been widely used for E. bieneusi genotyping, and more than 200 E. bieneusi genotypes have been reported in humans and animals [8, 9]
Prevalence of E. bieneusi in sheep in different regions of China Of the five regions tested for E. bieneusi infections in sheep, northeast China had the highest infection rate (38.5%, 50/130; 95% confidence intervals (CI): 30.1–47.4%), followed by northwest China (28.0%, 83/296; 95% CI: 23.0–33.5%), eastern China (17.8%, 58/326; 95% CI: 13.8–22.4%) and northern China (1.8%, 3/166; 95% CI: 0.4–5.2%)

Summary

Introduction

Enterocytozoon bieneusi is a common species of microsporidia that influences human health and threatens animal productive performance and value. Microsporidia are obligate intracellular eukaryotic parasites with a wide range of hosts that includes arthropods, birds, mammals and humans [1, 2]. The most common species, Enterocytozoon bieneusi [4, 5], can cause severe diarrhea in immunocompromised humans and animals, and Enterocytozoon bieneusi has frequently been reported in domestic animals and wildlife all over the world [7]. Polymorphisms in the ribosomal internal transcribed spacer (ITS) of the rRNA gene have been widely used for E. bieneusi genotyping, and more than 200 E. bieneusi genotypes have been reported in humans and animals [8, 9]. When analyzed in combination with phylogeny, these genotypes can be grouped into several genetically isolated clusters [10]

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